Nitrogen acyclic gold(I) carbenes: Excellent and easily accessible catalysts in reactions of 1,6-enynes

Complexes [AuCl{C(NHR)(NHR′)}] and [AuCl{C(NHR)(NEt₂)}] (R = tBu, p-Tol, Xylyl, p-C₆H₄COOH, p-C₆H₄COOEt, R′ = Me, nBu, iPr, nheptyl, p-Tol) have been prepared by reaction of the corresponding isocyanogold complexes [AuCl(CNR)] with either primary amines or diethylamine. All the prepared carbenes are reactive and highly selective catalysts for skeletal rearrangement, methoxycyclization of 1,6-enynes, and other mechanistically related gold-catalyzed transformations. Overall, these easily accessible nitrogen acyclic carbene (NAC) gold complexes were not second to NHC complexes and were advantageous to obtain different products.